Clamp for vulcanizing-molds



W. VANDERPOOL.

CLAMP FOR VULCANIZING MOLDS.

APPLICATON FILED AN.7. 1920.

1380354, Patente June 7, 1921.

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To all whom it nwy owem: i

Be it known that I, WILLIAM VANDEB- POOL, a citizen of the United States, residing at Springfield, in the count'y of Clark and State of Ohio, haveinvented, certain new and useful Im rovements in Clamps' for Vulcanizing-Mo ds, of which the following is a specification.

My invention relates to improvements in clamps for vulcanzing molds, particularly molds which are employed for retreading or patching the casings ofpneumatic tires.

.The object of my invention is to provide a clamp of acharacter which will permit it to yield to -compensate for the flow of the rubber compound during the process. of vulcanizaton or to any movement of the com-. pound within the mold due to contraction or expansion or: otherwise.

A further 'object of my invention is to provide aclamp of the character referred to which will be simple in Construction; efictive in` its operation, and which can be readily applied to the types of vulcanizing molds` now in general usefor tire repairing.

In the accompanyi'ng drawing, the figure represents a vertical section of a mold with atirc therein, showing my-improved clamp ap lied to it.

n the said drawing, 1' represents a vulcanzing mold of a kind' in common use for 4 tire repairing, the mold being provided with the usual steam chamber 2 and tire receiving' cavity 3. There is shown therein a section of a pneuma'tic tire casing 4 which has been retracted, 5 representing the tread shell which is usually glacedbetween the, tread of the tire and t e wall of the cavity 3. 6 is a core in the nature of a sandy bag, and 7 the core plate which is placed upon the ba and receives the pressure of the clamps.

v nretreading pneumatic tires, articu-` larly where a tread shell is employe which 'imparts a ribbed or other form ofrough tread surface to the tire, it has been found that the rubber compound -is slow to enter the interstices of the tread until after the rubber compound has become; heated to a 'certain degree to cause it to flow more freely. With the form of vulcanizing molds and clamping devices now in general use this frequently 'results in flaws n the tread v for the reasonthat when the rubber comound flows, the clampin e devices, articuarly the bag, fail to fo ow up an maintain' a umform pressure upon the interier Specmoation of'Ltte-s Patent.

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of the tire casing( 'Io overcome this dif-j m general use in a simple and effective manner and which will be eflective for the pur-` pose for which it is designed..

`In the drawin butone of these clamps has been shown', but 'it will be unders'tood that in *practice a plurality of the clamps are employed arran ed at suitable intervals along the mold. hreaded into, or otherwise engaged with, the walls of the moldat points directly opposite each other are two wrench or other tool. Straddling each of -posts 8 and 9, having heads 10 to receive a these posts is the bifurcated end of a crossbar 11 and between the ends of this crossbar and the heads 10 are placed coil springs 13. Threaded in the cross-bar 11--is a screw 12 having a head of suitable ,form to receive a wrench or other toolfor. the purpose of ti htening the screw against the core plate As the screw 12 is` tightene'd to position the cross-bar 11 will be caused to ride upwardly thereonv and compress the springs 13 so that the tension of the sprngs will apply a yielding pressure upon. the screw 12 through 'the cross-bar, and hence a yielding pressure upon the cores and the tire to cause the parts to settle or follow up the tread as it runs or contracts or to re lieve any expansion thereof. v v

By the use o a' clamp of this character, the same resul can be Secured as when the` more expensive air bag is used 'as a core, and a uniform tread free from flaws is insured and also a better union between the tread'and fabric.

Having thus described my invention, I claim i 1. In a clamp of the character described, the con bination of a vulcanizing mold, a pair of posts having an eng'agement with the walls of said mold at-points opposite each other, a cross-bar loosely mounted on said posts, 'springs between said cross-bar and abutm'ents on the posts, and a clamping gagemen't w ith the wails of sei& mol& ai', points opp oste each either, a cross-ber loosely mouted on 'the posts, springs be tween the cross-"bar and. abutments on the posts, and a screw threauded in the cross-ber errmged to appl'y pressure upon sasid com and also tension to the spring&

3. In a device of the character deseribe-,l the combnation of aL vulcaniz'mg mom e pair of opposiely' ermrge& posts owned 'by said mol& e cross-bar loosely 'moumfied on said posts a clamping' screw thx-%ded in said cross-ber, and means for applyng sprng-pressure to Seldi cross-bar..

I 44. In a devce of the character escribed, the combineton wto e vueanizing old having e tire recemng cevty and a core for the sime; of a pair of oppositely arrangel 'posts carred by seid mom, a; crossber loosely mounted on said. posts, e clamping' screw threaded in said dress-bar end extending to seid core, and 'means for applymg spring-pressure to said cross-bar.

Insestimony whereof, I have hereunto se& my' hand "this 83th day of January 1920.

. j WILLIAM VANDEPOOL Witzess:

- Cms. IQ Woman. 

